QNmeaPositionInfoSource Class
The QNmeaPositionInfoSource class provides positional information using a NMEA data source. More...
| Header: | #include <QNmeaPositionInfoSource> |
| qmake: | QT += positioning |
| Since: | Qt 5.2 |
| Inherits: | QGeoPositionInfoSource |
This class was introduced in Qt 5.2.
Public Types
| enum | UpdateMode { RealTimeMode, SimulationMode } |
Detailed Description
NMEA is a commonly used protocol for the specification of one's global position at a certain point in time. The QNmeaPositionInfoSource class reads NMEA data and uses it to provide positional data in the form of QGeoPositionInfo objects.
A QNmeaPositionInfoSource instance operates in either RealTimeMode or SimulationMode. These modes allow NMEA data to be read from either a live source of positional data, or replayed for simulation purposes from previously recorded NMEA data.
The source of NMEA data is set with setDevice().
Use startUpdates() to start receiving regular position updates and stopUpdates() to stop these updates. If you only require updates occasionally, you can call requestUpdate() to request a single update.
In both cases the position information is received via the positionUpdated() signal and the last known position can be accessed with lastKnownPosition().
QNmeaPositionInfoSource supports reporting the accuracy of the horizontal and vertical position. To enable position accuracy reporting an estimate of the User Equivalent Range Error associated with the NMEA source must be set with setUserEquivalentRangeError().
Member Type Documentation
enum QNmeaPositionInfoSource::UpdateMode
Defines the available update modes.
| Constant | Value | Description |
|---|---|---|
QNmeaPositionInfoSource::RealTimeMode | 1 | Positional data is read and distributed from the data source as it becomes available. Use this mode if you are using a live source of positional data (for example, a GPS hardware device). |
QNmeaPositionInfoSource::SimulationMode | 2 | The data and time information in the NMEA source data is used to provide positional updates at the rate at which the data was originally recorded. Use this mode if the data source contains previously recorded NMEA data and you want to replay the data for simulation purposes. |